Have you tried PortQuery? A command line tool for checking if a given port of a computer / server is open or shall we say “Listening”. Some of PortQuery links are found over here: http://support.microsoft.com/default.aspx?scid=kb%3ben-us%3b310099 and also on TechNet and if you look closely there are some samples also here: http://technet.microsoft.com/en-us/library/cc776894(WS.10).aspx
But that’s not entirely what this blog post is all about 😀 I was using PortQuery in a number of instance now and to my amazement, there is this little tool called PortQueryUI, Yes folks PortQuery with UI and not run from the CMD!. (And it runs without problems with my Windows7 workstation).
Just download and Unzip.
In this instance I need to use PortQueryUI to check if there is an existing SQL Instance in a remote server and Yes, the remote server indeed has an instance of SQL. It was indicated at the bottom TCP port 1433 (ms-sql-s service): LISTENING.
I tried this is on my localmachine (127.0.0.1). I did not installed any SQL Instance on my machine and upon checking, PortQuery reported NOT LISTENING. There is one more response that PortQuery is throwing, Filtered. For clarity I’ve copy pasted these from the KB article:
A process is listening on the port on the computer that you selected. Portqry.exe received a response from the port.
No process is listening on the target port on the target system. Portqry.exe received an Internet Control Message Protocol (ICMP) "Destination Unreachable – Port Unreachable" message back from the target UDP port. Or if the target port is a TCP port, Portqry received a TCP acknowledgement packet with the Reset flag set.
The port on the computer that you selected is being filtered. Portqry.exe did not receive a response from the port. A process may or may not be listening on the port. By default, TCP ports are queried three times, and UDP ports are queried one time before a report indicates that the port is filtered.
I’m really glad that old tools still run without problems with Windows7 🙂 So do check this out and to get the PortQryUI – User Interface for the PortQry Command Line Port Scanner from Microsoft Downloads: http://www.microsoft.com/downloads/details.aspx?familyid=8355e537-1ea6-4569-aabb-f248f4bd91d0&displaylang=en